Answer:
- Carryover effect
- Practice effect.
Explanation:
In within groups-design, a group of research subjects will be put into more than one different conditions / activities in order to measure the effect of each conditions/activities.
For example:
Let's say that a group of subjects is gathered for a 1 month long research. In the first two week, the subjects will be asked to follow a jogging regiment while in the second week the subjects will be asked to follow a swimming regiment.
Researchers want to measure which activities will be beneficial for their cardiovascular health.
There are a couple of problems in this type of research designs:
1. Carryover effect
In the experiment above, the health benefit that the subjects experience from jogging might be carried over and influence the results of the swimming period. This made the subjects started their second period of research in a better health than when they start at first.
This is called the carryover effect. This made it hard for researchers to truly know how much effect only swimming would provide since the data is mixed by the benefit from joggings.
2. Practice Effect.
If the subjects have done similar activities (jogging or swimming) in the past, their body will more likely become conditioned to do those activities and it would not experience as big of a transformation compared to the subjects that never did it before.
Answer:
Civilizations expand through trade, conflict, and exploration. Usually, all three elements must be present for a civilization to grow and remain stable for a long period of time.
Explanation:
I didn't find an exact answer, but i think this helps
Before the end of WWII in 1945 most of European countries were in constant wars with their neighbors. This was detrimental for the entire region because the fighting hampered efforts to develop a sustained economic growth. Due to these circumstances, the European Union was born to finally put an end to the endless wars among countries.
Around the 1950s, countries which were producing coal and steel in Europe, decided that in order to continue with the success of the two industries, it was necessary to unite European countries politically and economically and continue to enjoy the benefits of a good economy and to assure the stability of the region through a lasting peace.
The founder country members were France, Belgium, Italy, Germany, Luxembourg and the Netherlands. Thanks to their initiative, the European Union is what it is today, one the largest trading blocks around the world, and it is their hope that the lasting peace will continue for many more years.